The Ethernet Passive Optical Networks (EPON) protocol may be extended over coaxial (coax) links in a cable plant. The EPON protocol as implemented over coax links is called EPON Protocol over Coax (EPoC). An EPoC network or similar network may use multiple chunks of frequency spectrum and thus multiple channels for communication. Furthermore, different types of coax network units (CNUs) may be connected to the cable plant, with each type of CNU using a different set of channels. Scheduling transmissions on the different channels presents significant challenges.